• Tim Walz, the running mate of Democratic presidential nominee Kamala Harris, criticized the Republican ticket of Donald Trump and JD Vance as out of touch.
• Vance fired back in part by touting his poor upbringing and has since slammed Harris for wearing allegedly pricey jewelry in fundraising ads.
• The opening clash shows each presidential running mate vying to establish their ticket as being more authentic, more relatable and more in tune with the average American than their opponent's.

With their running mate selections, former President Donald Trump and Vice President Kamala Harris have opened up a new front in the battle for the White House: winning over the average Joe.

Courting "Real America" is hardly a novel campaign strategy — but it's one that Trump, a billionaire real estate magnate and media mogul, and Harris, a San Francisco career prosecutor turned politician, haven't leaned into.

In a country where roughly 130 million registered voters are either lower or middle income, however, waging class warfare is just good politics.

Enter Democratic Minnesota Gov. Tim Walz and Republican Sen. JD Vance of Ohio, the presidential candidates' running mates, whose modest backgrounds are central to their political personas.

In his debut on the Democratic ticket this week, Walz wasted no time trying to paint Vance as an out-of-touch elitist.

"Like all regular people I grew up with in the heartland, JD studied at Yale," Walz joked at a campaign rally with Harris in Philadelphia on Tuesday evening.

Vance "had his career funded by Silicon Valley billionaires, and then wrote a best seller trashing that community," Walz said, referring to the senator's hit memoir about his rural upbringing.

"Come on!" said the governor. "That's not what Middle America is."

The attack portrayed Trump's vice presidential pick as the near-total opposite of Walz, whom Harris had just introduced as "the proud product of a middle-class family in rural Nebraska."

Vance fired back Wednesday, calling Walz's remarks "pretty bizarre" and defending his rise through America's social and economic ranks.

"I grew up in a poor family" where nobody "had ever gone to law school," Vance said at a campaign stop in Michigan.

"The fact that Tim Walz wants to turn it into a bad thing, that I actually worked myself through college, through law school, and made something of myself — To me, that's the American dream," he said.

The opening clashes show each presidential running mate vying to establish themselves as being more authentic, more relatable and more in tune with the average American than their opponent.

It's a classic political tactic — but one that has only come to the forefront in the days since Walz and Vance joined the race.

"There's something strangely comforting about it," William Howell, a professor of political science at the University of Chicago, said in an interview.

"It's a longstanding feature of our politics, brought into stark relief in an age of acute inequality," Howell said.

"There are lots of things about this election that are unprecedented — this is not one of them."

President Joe Biden, who withdrew his reelection bid and endorsed Harris as his replacement in July, had kept the tradition alive and well.

He had fashioned himself an identity as "Middle Class Joe," touting his former status as the poorest member of the Senate and playing up his roots in blue-collar Scranton, Pennsylvania.

Harris, who was born and raised in deep-blue California and made her bones in San Francisco government, can make no such claims.

That could be a major problem for her efforts to win over key constituencies, such as rural, non-college-educated voters, that may sway the swing states that will decide the election.

As news outlet NOTUS put it: "Kamala Harris Has a Scranton Problem."

At her rally Tuesday, Harris initially skipped over Walz's political positions to praise his military service and his decades as a high school teacher and football coach. Walz was elected to Congress in 2006 and served in the House until he was sworn in as governor of Minnesota in 2019.

Vance, meanwhile, shot to national fame in 2016 after publishing "Hillbilly Elegy," a best-selling memoir recounting, and at times criticizing, the people and the Appalachian culture he grew up around.

He served in the U.S. Marine Corps and later graduated from Yale Law School. He won his first and only political race in 2022, for an open U.S. Senate seat in Ohio.

Now, both Walz and Vance are wielding their working-class bona fides against each other and against the top of the ticket.

In a Trump campaign fundraising email Wednesday morning, Vance attacked Harris for allegedly wearing a pricey necklace from Tiffany & Co. when she appeared in a campaign ad asking for donations to her presidential bid.

The email was written in Vance's voice, under the subject line, "This pic of Kamala pisses me off."

In it, Vance claimed Harris had "enriched herself from the DC Swamp so she can afford to wear necklaces that cost more than two months' wages."

A Harris campaign spokesman declined to comment on the Trump campaign's email.

Vance's attack on the vice president might have been muddled if had it come directly from Trump, who has long touted both his wealth and his affinity for gold and other high-end items.

In 2005, Trump bought his future wife, Melania Trump, an engagement ring that retailed for $1.5 million at the time, or roughly $2.4 million in today's dollars.

On Monday, Trump was gifted a Rolex watch and a Tesla Cybertruck during an interview with podcaster Adin Ross.

The following day, it was Walz, not Harris, who drew the sharp contrast between his own working class life experience and Trump's.

"Donald Trump's not fighting for you or your family," Walz told Tuesday's crowd in Philadelphia.

"He never sat at that kitchen table, like the one I grew up at, wondering how we were going to pay the bills. He sat at his country club up in Mar-a-Lago, wondering how he can cut taxes for his rich friends."

On Wednesday evening, Walz again targeted Trump with the same line of attack.

"My mom and dad taught us to show generosity toward your neighbors and to work for the common good," Walz wrote in a campaign email sent under his name.

"Donald Trump on the other hand? He sees the world differently. He doesn't know the first thing about  service because he's too busy serving himself."

A Trump campaign spokesman did not immediately respond to a request for comment.